What is an edge

[placeholder] Body content for this entry will be written by the copy chat. The entry covers what an edge is, why edges are first-class objects in Tree, and how they differ from the dependency fields you see in list-shaped tools.

In Tree, an edge points from a prerequisite node to a dependent node. When the prerequisite completes, the dependent's lock can lift.

Because edges are stored as their own records rather than as fields on a node, every dependency-aware operation (critical path, reachability, topological sort) is a graph query rather than a special case.